506.1. Accountable Player: The player responsible for putting a triggered ability on the chain, as defined by the core rules. See CR 383. Triggered Abilities for more information on triggered abilities.

506.2. Players are not required to notify other players of triggered abilities when they are not the accountable player, but may if they wish.

506.3. The accountable player must acknowledge their triggers by the time they would have an observable impact on the game. If they do not, they are forgotten.